Weather variables, water balance, growth, and agro industrial yield of sugarcane

The objective of this study was to evaluate the meteorological variables, water deficiency, growth, and agro-industrial yield of sugarcane varieties: RB72454, RB863129, RB867515, RB92579, RB93509, RB931003, RB951541, and RB971755, in rainfed crop in two harvests in the Rio Largo-AL region. The meteorological variables were obtained in an automatic station and water balance was done by Thornthwaite & Mather method. During the study period, the air temperature ranged from 16.6 to 35.9 ºC. In the first production cycle rained 1,806 mm and the crop evapotranspiration was 1,775 mm. In the second cycle, the rainfall totaled 1,632 mm and the crop evapotranspiration was 1,290 mm. The average water excess of two production cycles was 689 mm and the water deficit totaled 665 mm. The average agricultural productivity in the plant was 86.8 t ha-1, in the first ratoon was 75.2 t ha-1 and the agro-industrial yield average was 12.9 and 10.9 tons of sugar per hectare in the plant and first ratoon, respectively. The air temperature was not limiting to the growth of sugarcane and the rainfall was higher than the crop evapotranspiration, but due to poor distribution of the rains there was water deficit. The most productive varieties were RB93509, RB92579, and RB863129.O objetivo deste trabalho foi avaliar as variáveis meteorológicas, a deficiência hídrica, o crescimento e a produtividade agroindustrial das variedades de cana-de-açúcar: RB72454, RB863129, RB867515, RB92579, RB93509, RB931003, RB951541 e RB971755, em cultivo de sequeiro, em duas safras, na região de Rio Largo - AL. As variáveis meteorológicas foram obtidas em uma estação automática, e o balanço hídrico foi feito pelo método de Thornthwaite & Mather. No período da pesquisa, a temperatura do ar variou de 16,6 a 35,9º C. No primeiro ciclo de produção, choveu 1.806 mm, e a cultura evapotranspirou 1.775 mm, e, no segundo ciclo, a precipitação pluvial somou 1.632 mm, e a evapotranspiração da cultura foi 1.290 mm. O excesso hídrico médio dos dois ciclos de produção foi 689 mm; e o déficit hídrico, 665 mm. Ou seja, mesmo resultando em uma precipitação pluvial superior à evapotranspiração da cultura, devido à má distribuição das chuvas, houve deficiência hídrica. A temperatura do ar não foi limitante para o crescimento da cana-de-açúcar. A produtividade agrícola média da cana-planta foi 86,8 t ha-1, em cana-soca foi 75,2 t ha-1, e o rendimento agroindustrial médio foi 12,9 e 10,9 toneladas de açúcar por hectare em cana-planta e cana-soca, respectivamente. As variedades mais produtivas foram a RB93509, a RB92579 e a RB863129.Fundação de Amparo à Pesquisa do Estado de Alagoas (FAPEAL)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de Alagoas (UFAL)Universidade Federal de Campina Grande (UFCG)UNESP Botucatu.Universidade Estadual Paulista (UNESP) - Campus de Botucat

Morphological variables of sugar cane as a function of the water regime during initial development

Water deficit is one of the factors which most limit agriculture yield and growth. Although sugar cane has moderate tolerance to drought, it presents high yield losses under the influence of this abiotic factor. Based on this fact, selection of genotypes tolerant to water stress may represent an alternative for decreasing the amount of water used for irrigation, while keeping or increasing yield. This study was performed in order to evaluate the performance of four sugarcane cultivars during initial development under water stress conditions, by means of morphological variables to select more tolerant genotypes to drought. The experiment was carried out in a greenhouse at the Department of Rural Engineering, College of Agricultural Sciences - UNESP/Botucatu – SP, from November 26th 2010 to April 5th 2011. A total of four sugar cane cultivars were evaluated (RB855453, RB92579, RB965902 and RB965917) under two treatments as follows: control (100% field capacity) and water stress (50% field capacity). Evaluations were performed at 0, 28 and 63 days after treatment application. The following morphological variables were analyzed: plant height, leaf area, leaf length, leaf width, number of green leaves, shoot and root dry matter. The RB855453 and RB92579 cultivars produced more shoot and root dry matter under water stress treatment, while the RB965902 and RB965917 cultivars had lower shoot and root dry matter production under the same conditions. Therefore, the RB855453 and RB 92579 cultivars can be considered tolerant while the RB965902 and RB965917 cultivars can be considered susceptible.Dpto. de Produção e Melhoramento Vegetal, UNESPInstituto de Biologia, Dpto de Genética, Evolução e Bioagentes, UNICAMPInstituto Federal de educação, Ciência e tecnologia do Mato Grosso — Campus ConfresaDpto. de Engenharia Rural, UNESPDpto. de Produção e Melhoramento Vegetal, UNESPDpto. de Engenharia Rural, UNES

Weather variables, water balance, growth, and agro industrial yield of sugarcane

The objective of this study was to evaluate the meteorological variables, water deficiency, growth, and agro-industrial yield of sugarcane varieties: RB72454, RB863129, RB867515, RB92579, RB93509, RB931003, RB951541, and RB971755, in rainfed crop in two harvests in the Rio Largo-AL region. The meteorological variables were obtained in an automatic station and water balance was done by Thornthwaite & Mather method. During the study period, the air temperature ranged from 16.6 to 35.9 ºC. In the first production cycle rained 1,806 mm and the crop evapotranspiration was 1,775 mm. In the second cycle, the rainfall totaled 1,632 mm and the crop evapotranspiration was 1,290 mm. The average water excess of two production cycles was 689 mm and the water deficit totaled 665 mm. The average agricultural productivity in the plant was 86.8 t ha-1, in the first ratoon was 75.2 t ha-1 and the agro-industrial yield average was 12.9 and 10.9 tons of sugar per hectare in the plant and first ratoon, respectively. The air temperature was not limiting to the growth of sugarcane and the rainfall was higher than the crop evapotranspiration, but due to poor distribution of the rains there was water deficit. The most productive varieties were RB93509, RB92579, and RB863129.O objetivo deste trabalho foi avaliar as variáveis meteorológicas, a deficiência hídrica, o crescimento e a produtividade agroindustrial das variedades de cana-de-açúcar: RB72454, RB863129, RB867515, RB92579, RB93509, RB931003, RB951541 e RB971755, em cultivo de sequeiro, em duas safras, na região de Rio Largo - AL. As variáveis meteorológicas foram obtidas em uma estação automática, e o balanço hídrico foi feito pelo método de Thornthwaite & Mather. No período da pesquisa, a temperatura do ar variou de 16,6 a 35,9º C. No primeiro ciclo de produção, choveu 1.806 mm, e a cultura evapotranspirou 1.775 mm, e, no segundo ciclo, a precipitação pluvial somou 1.632 mm, e a evapotranspiração da cultura foi 1.290 mm. O excesso hídrico médio dos dois ciclos de produção foi 689 mm; e o déficit hídrico, 665 mm. Ou seja, mesmo resultando em uma precipitação pluvial superior à evapotranspiração da cultura, devido à má distribuição das chuvas, houve deficiência hídrica. A temperatura do ar não foi limitante para o crescimento da cana-de-açúcar. A produtividade agrícola média da cana-planta foi 86,8 t ha-1, em cana-soca foi 75,2 t ha-1, e o rendimento agroindustrial médio foi 12,9 e 10,9 toneladas de açúcar por hectare em cana-planta e cana-soca, respectivamente. As variedades mais produtivas foram a RB93509, a RB92579 e a RB863129.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq